A journal can be JNLC (move cash) or JNLS (move shares), dictated by entry_type. Generally, journal requests are subject to approval and starts from the pending status. The status changes are propagated through the Event API. Under certain conditions agreed for the partner, such journal transactions that meet the criteria are executed right away.
Idempotency: When the Idempotency-Key header is supplied, this endpoint is
idempotent. Multiple requests with the same key and identical request body will
create only one journal. A subsequent request returns the previously created
journal with the same response (no duplicate is created). If the same key is used
with a different request body, the API returns 422 Unprocessable Entity.
Recommended for production: Always supply Idempotency-Key when creating
journals. This allows safe retries on timeouts, network errors, or 5xx responses
without risking duplicate journals. Use a client-generated unique value (e.g. UUID).